It is known to equip a variable displacement compressor for an air-conditioner system with an electronic control valve (ECV). The compressor provides various passageways so pressure in various chambers within the compressor can be sensed by the ECV for the purpose of controlling the degree of displacement of the compressor. The chambers include a suction chamber having a suction pressure (PS), a discharge chamber having a discharge pressure (PD), and a crankcase having a crankcase pressure (PC).
The crankcase typically contains oil for lubricating various moving parts within the crankcase. However, the passageways and the configuration of the ECV create a path that oil from the crankcase can flow into the discharge chamber during shipping and handling of a new (i.e. not installed in a vehicle) compressor. When the compressor is installed on a vehicle, a discharge port plug is removed so the compressor can be connected to the rest of the air-conditioner system. If oil from the crankcase has accumulated in the discharge chamber, that oil may leak out of the compressor during the installation process and undesirably deposit on the vehicle or the person installing the compressor, and undesirably reduce the amount of oil in the compressor.